Fig. 1. Stable structures of two-dimensional VAene^[24]. (a) Schematic structures of α and β phases; (b) phonon spectra of α and β phases

Fig. 2. Stability and band structures of tetragonal system bismuthene ^[26]. (a) and (b) Schematic of tetragonal system structures; (c) molecular dynamics; (d) band structures caculated by PBE, PBE+SOC, HSE and HSE+SOC

Fig. 3. Point substituted defect structure monolayer bismuthene^[30]. (a) Density of states; (b) band structures

Fig. 4. Electrical conductance as a function of the bismuth thin film thickness at 300 K, 100 K and 5 K^[34]

Fig. 5. Bismuthene on SiC(0001)^[37]. (a) Sketch model of bismuthene on SiC; (b) STM image of bismuthene; (c) step height distribution map; (d) STM image with high resolution to show the honeycomb structure; (e) bismuthene honeycomb structure of the occupied states and the non-occupied states

Fig. 6. Atomic structure of bismuthene^[47]. (a) Top view; (b) side view; (c) schematic illustration of bismuthene preparation; (d) TEM image; (e) HRTEM image; (f) SEM image; (g) AFM image; (h) HRXRD image; (i) absorption spectrum; (j) Raman spectra of the bulk bismuth and the few-layer bismuthene; (k) XPS

Fig. 7. Sulfuric acid intercalation-assisted liquid exfoliation^[59]. (a) Schematic progress; (b) SEM image of bulk bismuth particle; (c) SEM image of sulfuric acid-intercalated bismuth powder; (d) SEM image of bismuthene nanosheets

Fig. 8. Few-layered bistmuthene mode-locked lasers^[47]. (a) Schematic diagram of bismuthene deposition; (b) microscope image of bismuthene saturable absorber; (c) nonlinear transmittance; (d) spectrum of mode-locking; (e) pulse train; (f) autocorrelation signal; (g) radio frequency spectrum

Fig. 9. Bismuthene mode-locking erbium-doped fiber laser^[53]. (a) Laser spectrum; (b) pulse train, inset: autocorrelation signal; (c) radio frequency spectrum; (d) output power versus the incident pump power

Fig. 10. Bismuthene mode-locked thulium-doped fiber laser^[59]. (a) Schematic diagram of laser cavity structure, inset: energy band structure with trap states; (b) pulse train; (c) pulse width, inset: spectrum

Fig. 11. Bismuth thin film mode-locked erbium-doped fiber laser^[79]. (a) Pulse train; (b) output mode-locked spectrum; (c) autocorrelation signal; (d) radio frequency spectrum; (e) pulse train from bismuth thin film Q-switched Er∶ZBLAN fiber laser; (f) output Q-switched spectrum

Fig. 12. Bismuthene Q-switched laser^[80]. (a)--(c) Pulses with different time scales; (d) output spectrum